That is, bluntly, something we're not going to be able to pay off. So there'll be a bankruptcy, either cutting those social security checks to a fraction of the promised size, or inflating the dollar until the promised amount is worth almost nothing.

But in all those presidential debates no one asks, "Senator X, the federal debt will break $20 trillion during your first term. What will you do if the financial markets don't supply the loans your administration asks for?"